Checksum from .iso

I had the iso image but I deleted his.Previously I recorded this .iso file on DVD disc.Now i want check md5, sha1, crc32 this .iso file (now I did from DVD disc – .iso file with program Poweriso).Is the checksum will match to the original .iso file ?
Answer #1
what exactly are you asking? sorry having trouble understand…you burned a iso to a dvd and deleted the iso off your pc?
Answer #2
No, I don’t think you can. Once the original ISO is destroyed, re-creating it exactly as it was is extremely difficult unless you know exactly how it was originally created because if one bit is different or there is one extra byte in the file, the checksum hash will not be identical.
Answer #3
Yea, right this is impossible.
How to check at 100% in OS (for example, someone/uploader modified the original DVD with OS) does not have sewn the back door etc.?
Answer #4
That’s just it………you can never know 100% that someone hasn’t added a trojan, virus, keylogger, rootkit to a windows cd/dvd image without checking the ISO hash. Some rootkits are not detectable so you would never know! That’s why I never download windows iso without being able to check the file hash to confirm that it has not been altered. I don’t care about convenience, drivers added or tiny, faster, better or whatever, all I care about is a genuine windows cd/dvd which I know is 100% clean. That’s where I always start from.
Checking and attempting to rule out an infection is the best you can do, but that isn’t safe enough for me. This might help a little but not 100% effective. Doing all the online scans you can might provide a further check but it’s easy to miss stuff that knows how to remain hidden and undetectable.
http://www.hijackthis.de/
http://www.novirusthanks.org/hijackthis-logs-reader
Be careful with this one, only use it with help from someone who knows how to use it. No PM’s on this, others will help.
http://www.bleepingcomputer.com/combofix/how-to-use-combofix